RHSA-2026:18683 — Security Advisory

An update for libssh is now available for Red Hat Enterprise Linux 9.

Red Hat Product Security has rated this update as having a security impact of Moderate. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

libssh is a library which implements the SSH protocol. It can be used to implement client and server applications.

Security Fix(es):

• libssh: Double Free Vulnerability in libssh Key Export Functions (CVE-2025-5351)

• libssh: Use of uninitialized variable in privatekey_from_file() (CVE-2025-4878)

• libssh: Write beyond bounds in binary to base64 conversion functions (CVE-2025-4877)

• libssh: NULL Pointer Dereference in libssh KEX Session ID Calculation (CVE-2025-8114)

• libssh: Memory Exhaustion via Repeated Key Exchange in libssh (CVE-2025-8277)

• libssh: Buffer underflow in ssh_get_hexa() on invalid input (CVE-2026-0966)

• libssh: Improper sanitation of paths received from SCP servers (CVE-2026-0964)

• libssh: libssh: Denial of Service via improper configuration file handling (CVE-2026-0965)

• libssh: libssh: Denial of Service via inefficient regular expression processing (CVE-2026-0967)

• libssh: libssh: Denial of Service due to malformed SFTP message (CVE-2026-0968)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Additional Changes:

For detailed information on changes in this release, see the Red Hat Enterprise Linux 9 Release Notes linked from the References section.